A liquid crystal display element integrated with a touch sensor as described in Japanese Patent Laying-Open No. 2001-75074 (PTL 1) includes a first substrate, a second substrate, and a liquid crystal layer inserted between the first substrate and the second substrate. A display electrode for image display and a touch electrode for touch point detection are provided on surfaces of the first substrate and the second substrate facing each other.
A position pressure detector described in Japanese Patent Laying-Open No. 2005-233798 (PTL 2) includes a base having a resistance film on one side thereof and a base having a conductive material on one side thereof. The resistance film and the conductive material are arranged to face each other, and a spacer is provided between these bases. A voltage is supplied to a pair of electrodes at the opposing ends of the resistance film, such that a voltage of the resistance film increases linearly from the one end side to the other end side of the resistance film. The conductive material is provided with an electrode. The position pressure detector further includes a circuit outputting a position signal based on a signal obtained from the electrode of the conductive material, and a circuit outputting a pressure signal based on a signal obtained from the pair of electrodes at the opposing ends of the resistance film.
A display device with an input function described in Japanese Patent Laying-Open No. 2002-287660 (PTL 3) includes a first substrate, a second substrate, a contact position detecting electrode formed on the first substrate and protruding from this first substrate toward the second substrate, a first contact position detecting signal line formed on the first substrate and electrically connected to the contact position detecting electrode, and a second contact position detecting signal line formed on the second substrate.
A liquid crystal display device described in Japanese Patent Laying-Open No. 11-271712 (PTL 4) includes an array substrate, a common substrate, a spacer for keeping a gap between the array substrate and the common substrate, and a pressure detecting element sandwiched between the spacer and the common substrate. An element formed by dispersing conductive fine particles onto an insulating material, a piezoelectric body generating surface charge, and the like are used as the pressure detecting element.
Various types of pressure sensors have been conventionally suggested. For example, a touch-mode capacitive pressure sensor described in the Fujikura Technical Review includes a diaphragm deformed by the applied pressure, a substrate facing the diaphragm, an electrode formed on the substrate, and a dielectric film formed on the electrode.
A pressure sensor described in Japanese Patent Laying-Open No. 2002-318163 (PTL 5) includes an insulating porous sheet and metal layers formed on upper and lower surfaces of this insulating porous sheet. The insulating porous sheet is made of polyethylene, polyester, polyimide, PTFE, polypropylene, polycarbonate, polysulfone, polyvinylidene fluoride, polyacrylonitrile, polyamide, cellulose acetate or the like.
A sheet-like pressure sensor described in Japanese Patent Laying-Open No. 2003-75277 (PTL 6) includes electrodes facing each other and a pressure-sensitive layer formed between these electrodes and changing a dielectric constant by pressure. A surface pressure distribution sensor described in Japanese Patent Laying-Open No. 2004-317403 (PTL 7) includes a line wiring part and a column wiring part arranged to face each other with a certain spacing therebetween via a spacer. The line wiring part includes a glass substrate, multiple line wirings aligned in parallel to one another in a first direction on this glass substrate, and an insulating film covering these line wirings. The column wiring part includes a flexible film and multiple column wirings aligned in parallel to one another in a second direction on this flexible film.
A pressure detector described in Japanese Patent Laying-Open No. 2005-181031 (PTL 8), Japanese Patent Laying-Open No. 2005-233798 (PTL 2) and the like includes a base having a resistance film on one side thereof and a base having a conductive material on one side thereof. The resistance film and the conductive material are arranged to face each other, and a spacer is provided between these bases. A voltage is supplied to a pair of electrodes at the opposing ends of the resistance film, such that a voltage of the resistance film increases linearly from the one end side to the other end side of the resistance film. The conductive material is provided with an electrode. The pressure detector further includes a circuit outputting a position signal based on a signal obtained from the electrode of the conductive material, and a circuit outputting a pressure signal based on a signal obtained from the pair of electrodes at the opposing ends of the resistance film.